#board {
    width: 500px;
    height: 500px;
    background-color: gray;
    margin: 0 auto;
    position: relative;
}

#myTK {
    position: absolute;
    text-align: right;
    background-color: blue;
    color: white;
}

.tk {
    position: absolute;
    width: 25px;
    height: 25px;
    text-align: right;
    background-color: red;
    text-align: right;
    color: white;
}

.qiang {
    position: absolute;
    z-index: 2;
}

#btns {
    width: 300px;
    margin: 0 auto;
}

#btns button {
    width: 100px;
}

#btns button {
    /* display: none; */
    float: left;
}

#score {
    float: right;
}

ul {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
    width: 60vw;
    height: 60vw;
    margin-left: auto;
    margin-right: auto;
    position: relative;
}

ul#control li {
    box-sizing: border-box;
    list-style: none;
    margin: 0;
    padding: 0;
    padding: 6px 0;
    background-color: gray;
    width: 20vw;
    height: 20vw;
    position: absolute;
    color: white;
    font-weight: bold;
    font-size: 30px;
    text-align: center;
    cursor: pointer;
    border: white 1px solid;
    transform: rotateZ(45deg);
}

.l1 {
    left: 20vw;
    top: 5vw;
    border-radius: 50% 0 0 0;
}

.l2 {
    left: 35vw;
    top: 20vw;
    border-radius: 0 50% 0 0;
}

.l3 {
    left: 20vw;
    top: 35vw;
    border-radius: 0 0 50% 0;
}

.l4 {
    left: 5vw;
    top: 20vw;
    border-radius: 0 0 0 50%;
}

#fire {
    width: 100px;
    height: 100px;
    border-radius: 50%;
    float: right;
    outline: none;
    display: none;
}

#add {
    margin-left: 30px;
}

#as {
    width: 200px;
    margin: 0 auto;
    clear: both;
}

ul#control {
    display: none;
}

@media screen and (max-width:500px) {
    .tk {
        width: 15px;
        height: 15px;
    }
    ul#control {
        display: block;
    }
    #fire {
        display: block;
    }
}